Safety-switches for making and breaking electric circuits



March 1958 w. c. WILSON ET AL 2,82

SAFETY-SWITCHES FOR MAKING AND BREAKING ELECT RIC CIRCUITS Filed July 25, 1954 2 Sheets-Sheet 1 IN VEN TORS AL V4 t/- B/SHOP, UP. W/LL/AM 6. WA! SON March '11, 1958 w. c. WILSON ET AL 2,826,662

SAFETY-SWITCHES FOR MAKING AND BREAKING ELECTRIC CIRCUITS Filed July 25, 1954 2 Sheets-Sheet 2 INVENTORS AZ VA J. B/SHOP, JR. WILL/AM C. W/ASO/V United States PatentO SAFETY-SWITCHES FOR MAKING AND BREAK IN G ELECTRIC CIRGUITS:

William C. Wilson and Alva 1. Bishop, In, Zanesville, Ohio.

Application July 23; 1954,,SeriaLNo. 445,378.:

4 Claims. (CL 200 -165) This invention" relatesto improvements inn safetyswitches. for making and breaking electric! circuits such as. the battery circuits in automobiles, and also circuits in buildings and the. like.

One of the objects of our invention is to: produce a safety-switch for use primarily in the ground circuitof an automobile battery but which may be employed 'for opening and closing an electric circuit generally; occupies a minimum amount of space or room; andwhich will comprise conical switch members mounted to producea simple; rugged construction that will enable ready, quick and easy assembly of the parts into a: highlywefiieient switch: which will avoid mechanical failure, may-"beoperated with great facility: and which will be operable, upon; 21- making operation; to provide immediately arr ih creased area of contact and upon a' di'sconnecti'ng'on opening operation will producean immediateand' complete breaking of the' circuit.

Another object of ourinvention is to'provide a-switch for-connecting and disconnecting the ground circuit from the battery circuit ofan automobile whichmayb'e op erated by the use of a controlling element placedin a convenient location-for an operator of'avehicleto permit instantaneous operation generallyand 'also; in case of a short circuit in wiring causing 'fire; the operatonof the vehicle can pull the control cord and disconnecti'a'll the current from thebattery.

Another object of our'invention' is to provide-a switch of the type specified' whichi may be readily andquickly operated, and which will not onlystop a fire in a vehicle caused by defective wiring but will enable the, prevention of a fire: in any vehicle by turning the control to on? positionwhen the vehicle is not in use suchas when a car is parkedin agarage under ahouse, or close to aJiouse, tractorsand farmmachinery,-. parked in .barns, houses boats etc;

Another object of our invention is to..provide a switch construction in which conical switch members are so arranged in relation to each other and also ali'gnediand guidedin their relative movements. to causethe circuit upon a making operationto be instantly: and completely closed without any drag, and in a 'breakingoperation to cause such conicalswitch members to be instantly and positively separated; to completely'and instantly break the circuit.

Another object of our. invention isto provide a cone. switch in which. one ofthe conical switch memberswill comprise a fixedly-supported. inwardly-projecting, cone which is completely insulated from other partsaand is combined. with amovable member embodying a. conical depression of identicali'magnitude tojthe fixed. projecting cone...

' Another, object. of...our inventionisto. provide. means for movably mounting said. movable conical switchmem: her in relationflto said. fixed: conical members. to produce precise registration of the .twomembers.

} Another objectyof our. invention is totutilizera compact switch having a supportingstructure enclosing the: movable partswand comprising arugged, cylindrical casing closed at one end-by a fixed transversely disposed discshaped top, the upper-surfaceof which is adapted to be utilized as a cam-mounting surface crepe-rating table, while the body of said disc-shaped top is employed'as a fixed support for one end of a' plurality and preferably of threeguiding elements ori'posts which surround the axis of" the casing andserve to mount, align and guide the-movable conical switch-member in its movements into engagement and. disengagement with the fixed projecting cam element.

Another object of our invention is in a'deviceof the character specified to provide for operative: movements of the" movable conical l switchmember by springs and a cam having amounting stem axially connected with and operable to instantly move the movable conical switch member into or out of complete connection or disconnection with" the fi xed conical switch member.

Another object of our invention is to utilize at the bottom end of the casing" an axially-positioned connecting element to connect our fixed'conical switch member to a battery terminal in a circuit andto utilize forconcam" construction in which the cam comprises-atsiinple metallic plate having at one.end a. pointed rectangular cam surface: that provides for a cam movement by positioningan axle member to one side ofthe axis of the pointedfcam element, and thus. by a tilting of" the cam enabling aliftingof the. connectingstem above the top ofthe cam cream-operating table. and? a consequent disconnection of. the conical switch members.

With these and other objectsin view, the invention comprises the combination of members and arrangement ofjparts so combined as to co-act and. cooperate withaeach other in the performance of the functionsv and the accomplishment of the results. herein contemplated; and comprises in one ofits adaptations the species or preferred form illustrated in the accompanying drawings,,i'n.whichk Fig. l is a view in side elevation of a. switchaof. our connection. connected up. to the battery and ground...cir-. cuit of an automobile, the parts-being .shown. in open position; r

Fig. 2 is a top plan. view of the switch. shownih Fig. l;

Fig.v 3 is a. center, longitudinal, section. showing the cam in operative position. to move the parts. to prod'uce a breaking of the circuit;,

Fig, 4 is a similar section. showing; the cam in: an operative position to close the circuit.

Referring now to these drawings. which. illustrate a preferred. embodiment ofour. invention, 10;. indicates .a rugged andstrong cylindricalzcasing; closed-atait'supper end. with. an. integral, discsor endaplatenlS to: provideuan enclosing casing for the working; parts oft. our: switch. The integral disc 13 providesontitsoutensurfacei a' camsupporting table= andwthe body oft said:.d i sc: providesr a support for, one; end. of'each of a series, of guide":-ro d s 1.4 asrhereinafter. specified...

The casing 10. in the embodimentshowm is. provided intermediate its ends with a base 11 adapted to permit mounting of the switch on a fire wall 12 of an automobile, said base 11 having flanges adapted to lie flat against and to be connected to said fire wall 12.

In the embodimentshown, the integrahend: plate or disc -13 serves-as aboveindicated as a support for the .upper; or innerends 14 of-a series? of three rods or posts 14 'which arepositioned to surround the axis of the cylinder. Each rod or post is screw-threaded and firmly supported and held in place at its upper end within the casing'by; nuts 15;, The guide rods 14 have their opposite ends 'fixedly;mounted, and supported by screws and nuts 14?-in;a thick, sturdy insulating ring 16 which closely fits the lower rim portion of our cylindrical casing, and'thus'firmly' heldin; place within said i'im portion by said rods or posts and has a thick; outer edge-that-abuts-theinner surface of the casting to as- .into and held within said ring of insulating material.

Said fixed conical switch member 17 has axially projecting outwardly from the base thereof a heavy screwthreadedconnecting element 18 provided with suitable nuts 19 forthe purpose of securely connecting to said fixed conical switch member a terminal of an automobile battery cable 20 which leads to a battery or batteries,

not shown.

Slidably' mounted within the casing 10. on the rods .14 and movable into and out of'contact with said coneshaped head portionof said fixed conical switch member 17 is a movable conical switch member 21 having a conical socket 22 adapted to-match and closely fit the cone-shaped head 17 of the fixed conical switch member 17.

The socketed conical switch member 21 has projecting from its side circumferential surface a heavy screwthreaded cable-securing connecting element 23 which is alsoprovided with nuts 24 for the purpose of securely attaching thereto a ground cable 25, the opposite end of which will in the conventional manner be connected to.the ground or chassis of anjautomobile. As shown, the connecting element 23 carries a ferrule 23* which extends 'outwardlyfrom a suitable position on the circumference of the socket member 21 and encloses the connecting element 23. Said ferrule 23 and screw 23 are thus adapted to move or slidingly reciprocate within a vertical guide slot in the cylindrical side wall of the casing 10.

In Fig. 3 the movable conical socketed switch member 21 and the fixed projecting conical member 17 are shown in separated or circuit-breaking open position while in Fig. 4 the movable conical socketed member 21 is shown in closed circuit-making position. Movement of the two members is effected as follows:

The movable socketed switch member 21 has projecting axially upwardly therefrom a screw-threaded bearing element 21 having at its upper end a pivot 26 about which an operating cam element 27 composed of a narrow flat plate having a pointed lower end formed between its side edges by a rectangular surface 27 having its pointed end arranged centrally of the element 27' and about which the said element is adapted to be rocked. The said pointed rectangular surface is con- 4, to be moved about the pivot 26 for the purpose in one tilted position of raising the movable socketed switch member 21 in relation to the casing 10 to break the circuit and in its opposite tilted position permitting said switch member 21 to be lowered into circuit-making position with the switch member 17.

In Fig. 3 the cam member 27 has been moved about its pivot to an inclined position which causes engagement with the table top 10% of that portion of the cam surface which is more remote from the pivot, thus producing a lifting of said member 21 and causing the wall of the socket 22 of the switch member 21 to be moved upwardly out of contact with the conical surface 17 of the switch member 17. a

In Fig. 4, the cam member 27 has been swung about its pivot to an inclined position opposite to that shown in Fig. 3 in which the cam surface that is closer to the pivot engages with the table top, thus permitting a lower- .ingof said switch member '21 into a position in which the wall of the socket 22 of said switchmember will have contact with the conical surface 17 of switch member 17. In ,order to positively move said socketed member into contact with said projecting conical member 17, we provide three springs 14 which are positioned to surround the axes of the said conical switch members and are preferably, mounted on the three posts 14. v

Suitable means is provided for manually swinging the operating cam member 27 about its pivot to the positions above specified, and, as illustrated, we have for this purpose shown a rod 28-connected at one end to said cam 27 and extending through a tube 29. The rod 28 passes through automobile walls and has a portion 28 connected to a handle 30 on the dash-board of a vehicle.

Obviously, in operation, when the operating element 27 'is manually moved to the inclined position shown in Fig.4 the switch members 21 will be automatically moved by expansion of' the springs -14 into close contact with the member 17 and when said member 27 is manually swung into the position shown in Fig. 3 the action of the cam will compress the springs and cause a separating movement of the switch members.

It will be understood that by the utilization of the conical switch member 17 with its conical surface 17 in axial alignment with-the conical socket 22 in the switch member-21, a cool contact mechanism will be produced for the purposes specified in the object clauses hereinabove specified.

It will also be understood that the use of conical surfaces provides nruch larger contact surfaces than conventional switches and these two conical surfaces when aligned andmoved'into complete contact with each other by the use of a series of guide rods that surround the axes of. the two switch members provide a switch constructionthat will possess the many advantages hereinabove specified.

: Having described our invention, we claim:

1. A safety switch for making and breaking electric circuitscomprising a pair of mating conical switch members composed of current-transmitting material, said pair composed of a fixed projecting cone provided with a continuous conical surface and a movable switch member of greater diameter and having at its axis a matching conical'socket provided with a similar continuous switch contact area adapted to fit over and produce conical contacting surfaces of large diametric dimensions and wide cylindrical body portions surrounding said socket, means for supportingsaid projecting-conemember in fixed position compiising an insulating disc, means for mounting the movable member to move axially into and out of elec trical-contacting engagement with its mate, guiding means positioned in said wide body portion at a plurality of points surrounding the socket in said movable member and extending parallel to the axis thereof for aligning the same to simultaneously produce a complete contact of essence the switch contact areas thereof with the contact areas of its mate, means for individually connecting said switch members in an electric circuit, operating means for moving said movable switch member axially into circuitbreaking position, and means operable upon the release of said operating means for automatically moving said members to circuit-making position.

2. A safety switch for making and breaking electric circuits comprising a pair of mating conical switch members composed of current-transmitting material, said pair composed of a fixed switch member provided with a con tinuous conical surface and a movable switch member having at its axis a matching conical socket and provided with a similar continuous switch contact area adapted to fit over and produce conical contacting surfaces of large diametric dimensions, means for supporting one of said cone members in fixed position, means for mounting the movable member to move axially into and out of electrical-contacting engagement with its mate, guiding means surrounding the conical portion of said movable member and extending parallel to the axis thereof for aligning the same to simultaneously produce a complete contact of the switch contact areas thereof with the contact areas of its mate, means for individually connecting said switch members in an electric circuit, operating means comprising cam mechanism connected axially to the movable member of said pair of switch members and having a pair of cams, one of which is a circuit-breaking cam operable to move and retain the movable switch member into circuit breaking position, and the other cam member of said pair of cams comprises a circuit-making cam operable upon the release of said circuit-breaking cam to automatically move said switch member to circuit-making position and to retain the same therein.

3. A safety switch for making and breaking electric circuits comprising a support composed of a cylindrical casing having at one end an integral disc closing said end and serving as a cam-supporting table, a pair of mating conical switch members mounted within said casing and composed of current-transmitting material, one member of said pair comprising a fixed switch member provided with a continuous conical surface and the other switch member comprising a movable disc having at its axis a matching conical socket and provided with a similar continuous switch contact area adapted to fit over and produce conical contacting surfaces of large diametric dimensions, means at the opposite end of said casing comprising a flat insulating disc and contacting and insulating the fixed member and for supporting said fixed member in fixed position, means for mounting the other member within the body of said casing to move into and out of engagement with its mate, guiding means for aligning the same to simultaneously produce a complete contact of the switch contact areas thereof with the contact areas of its mate, means for individually connecting said members in an electric circuit, and operating means for moving said movable switch member comprising cam mechanism mounted on said cam-supporting table and connected axially to the movable member of said pair of switch members, said cam-mechanism comprising a pair of cams operable by movement in opposite directions, one of which cams is a circuit-breaking element operable to move and retain the movable switch member into circuit-breaking position, and the other cam member of said pair of cams comprises a circuit-making cam operable upon the release of said circuit-breaking cam to automatically move said switch member to circuit making position and to retain the same therein.

4. A safety switch for making and breaking electric circuits comprising a support composed of a cylindrical casing having at one end an integral disc closing said end and serving as a cam-supporting table, a pair of mating conical switch members mounted within said casing and composed of current-transmitting material, one member of said pair comprising a fixed switch member provided with a continuous conical surface and the other switch member comprising a movable disc having at its axis a matching conical socket and provided with a. similar continuous switch contact area adapted to fit over and produce conical contacting surfaces of large diametric dimensions, means at the opposite end of said casing comprising a flat insulating disc and contacting and insulating the fixed member and for supporting said fixed member in fixed position, means for mounting the other member within the body of said casing to move into and out of engagement with its mate, guiding means for aligning the same to simultaneously produce a complete contact of the switch contact areas thereof with the contact areas of its mate, means for individually connecting said members in an electric circuit, and operating means for moving said movable switch member embodying cam mechanism connected axially to the movable member of said pair of switch members and comprising a single pointed cam element having an eccentric connection with the axis of said movable member to provide a pair of cams operable by movement in opposite directions of the cam element about its point and one of which pair of cams is a circuit-breaking cam operable to move the movable member into circuit-breaking position and to retain the same therein, and the other member of said pair of cams comprises a circuit-making cam operable upon the release of said circuit-breaking cam to automatically move said members to circuit-making position and to retain the same therein.

References Cited in the file of this patent UNITED STATES PATENTS 1,865,003 Hall June 28, 1932 1,984,921 Ehrlich Dec. 18, 1934 2,170,961 Borgkvist Aug. 29, 1939 2,473,303 Robbins et a1. June 14, 1949 

